This invention relates to pointing interfaces for human interaction with display-based computer systems.
Pointing is one of the simplest ways for a person to indicate his wishes or convey information to others. And pointing (for example, to words written on a whiteboard, or to parts of a painting represented on a projected image, or to places on any of the infinite variety of real-world objects) is one of the most common aids to conversation, instruction, and cooperative effort.
Pointing devices run the gamut from fingers, pointing sticks, and other mechanical and illuminated instruments, to light pens, touch pads, computer mice, touchscreens, and other electromechanical and electronic pointers. Pointing may be direct pointing along a line of sight to a target (as when a pointing device is directly aimed at a portion of display of a radiated or otherwise projected image) or indirect pointing (as when a mouse is manipulated to control the position of an image of a pointer on a display, without pointing the mouse itself at the display).
When the pointing is directed to a place on an object which is being shown on an electronic display (e.g., to a command icon appearing on a CRT), the act of pointing must be linked by some sort of electronic processing to the target command icon.
In the case of a mouse, the identity of the target command icon may be inferred from the location of the pointer on the display at the time of a mouse click. In the case of a light pen, the raster scanning of the display permits a one-to-one mapping of moments in time to points on the display so that the moment when light from the target location is detected by the pen implies the target location.
In one traditional class of computer interface, the user types sequences of text commands to control what the computer does. Also common are menu driven systems in which the user makes selections of actions from predetermined lists. In recent years graphical user interfaces (e.g., the Microsoft Windows interface) have become popular. In a typical graphical user interface, the user causes a displayed pointer to move across the display by manipulating a mouse and xe2x80x9cclicksxe2x80x9d a mouse button to indicate an action.
The invention provides a visual interface which is virtually as natural as the simple human act of pointing with a finger to any place or sequence of places within a person""s field of view. Unlike a keyboard, the interface is not confined to a limited number of actions but enables unconstrained pointing motion in any direction. Unlike a mouse or track ball, the user is not obligated to make a complex mental connection between motions of the device and a cursor on the screen. Also unlike a mouse or track ball, the user""s pointing can jump rapidly among a succession of places on a display and yet the system is capable of determining immediately the absolute location of each place on the screen, rather than requiring the determination to be made relative to the prior target. Unlike a touch screen or similar device, the user need not be within arm""s reach of the display, but could be across the room or in an auditorium. The display part of the interface could be as small as a single screen or as large as a wall-size array of screens. The places to which the user is pointing need not even be on a computer screen but could be on everyday objects, e.g., a painting hanging on a wall, provided that appropriate scanning equipment is used. The object need not even be planar. Furthermore, two, three, or even more users may interact with the interface simultaneously and independently, with the system immediately determining the absolute locations of the places to which each user points. In one mode of use, several users could interact with one another and with a computer display (or displays) while moving around a room and pointing at different parts of the display (or displays) in a completely natural way.
In one general aspect of the invention, the interface includes a hand-manipulated pointer configured to permit it to be (1) aimed by line of sight to point at any arbitrary position within the user""s field of view, including positions beyond the user""s natural reach, and (2) swept along any arbitrary path and at any arbitrary speed within the user""s natural capability. A detector (e.g., in the pointer, or associated with it) detects emanations (from the display) from at least some positions at which the pointer may be aimed; and circuitry identifies the locations of positions at which the user is aiming the pointer (and thus aids in determining, e.g., the timing of events and the identity of the user). The interface enables the user to point to a position within his field of view and beyond his reach, move his hand along any arbitrary path and at any arbitrary speed within the user""s natural capability to point to another position, and so on, and to have the circuitry automatically identify the locations of the series of positions to which he has pointed.
Implementations of the invention include the following features. The circuitry (which may or may not be located in the pointer) identifies the location, within a coordinate system, of each position in the series of positions. An event generator (e.g., a push button on the pointer) enables the user to generate events associated with positions at which the user is aiming the pointer.
The emanations differ at different positions, and the circuitry identifies the location of each position based on differences in the emanations. The differences in the emanations may comprise differences in time of occurrence, e.g., those associated with raster scanning of the positions. The arbitrary positions to which the pointer may be aimed may lie on a substantially planar surface on a pixel image display device, e.g., a raster scanned CRT. Some implementations may use a static display and may impose a raster-like scan on the static display by altering the appearance of successive lines shown on the static display.
The emanations may include electromagnetic radiation, such as visible light or non-visible infrared radiation. In some implementations, the emanations may originate at their positions on the display. In some implementations, the emanations may only be reflected from the positions. In the latter case, the reflections may be of scanned emanations, e.g., a vertical or horizontal line of emanations (whether visible or not) scanned across a static screen or even an everyday object.
The detector in the pointer may be of the kind that separately detects emanations received at multiple receivers (e.g., multiple independent sensors in the pointer), and the system may include circuitry for generating a monopulse position estimate based on the emanations received at the multiple receivers. The detector, the circuitry, and the event generator all may be part of the pointer. The events generated by the event generator may be event signals delivered by wire or by electromagnetic radiation.
There may be a second (and a third or more) hand-manipulated pointer(s), detector(s), and event generator(s); and the circuitry may also identify the location of each position at which the other pointers are aimed.
The arbitrary positions to which the pointer may be aimed may lie on a display system of multiple, separately scanned pixel image display surfaces. The interface may enable the user to point to a position on any one of the display surfaces, move his hand along any arbitrary path and at any arbitrary speed within the user""s natural capability to point to another position on another one of the display surfaces, and so on, and to have the circuitry automatically identify the locations of the series of positions to which he has pointed. The display surfaces may be raster scanned using respective timing signals which may be synchronized or unsynchronized among the display surfaces.
A display identity detector (within the pointer or external to it) may detect on which display is the position at which the pointer is aimed. The display identity detector may include multiple spaced-apart sensors which detect emanations from the pointer, and a monopulse circuit which delivers a signal identifying the display at which the pointer is aimed, based on the emanations detected at the multiple sensors. The pointer may include a source oriented to deliver electromagnetic radiation to the spread-apart sensors. The image display surfaces may be rectangular and arranged in an array, and the sensors may be located at the corners of the display surfaces. The monopulse position signal may generate information associated with the rotational orientation of the pointer. Alternatively, the scan lines of the different displays may be generated in different colors which would enable the determination of the display at which the pointer is aimed to be determined by the pointer.
Other advantages and features of the invention will become apparent from the following description and from the claims.